Posts Tagged "black carbon"

Roundup: Bubbling Ice, Black Carbon, and Glacial Advance

Posted by on Jun 1, 2015 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Bubbling Ice, Black Carbon, and Glacial Advance

Spread the News:ShareThe sound of glaciers A new article in the scientific journal Geophysical Research Letters, titled Unusually loud ambient noise in tidewater glacier fjords: A signal of ice melt, tracks glacial melt by recording the sounds of the glaciers bubbling underwater in glacial bays. Check out videos of the unique sounds below, and read the article here. http://glacierhub.org/wp-content/uploads/2015/06/grl52695-sup-0003-MovS3.mp4   http://glacierhub.org/wp-content/uploads/2015/06/grl52695-sup-0004-MovS4.mp4 “After decades of retreat, in the 1980s, many Karakoram glaciers suddenly ‘changed their mind.'” According to Kenneth Hewitt, a glaciologist at Wilfrid Laurier University, Waterloo, in Canada, ‘I began to see glacier thickening and advancing that I had not observed in the 35 years of field work before.’ Hewitt called it the ‘Karakoram anomaly,’ and climate-change skeptics made the most of it. Read the full story by Jane Qiu in Science. New Report on Black Carbon in the Peruvian Andes According to the study, tropical glacial melt is rapidly affecting water supplies and high concentrations of “light-absorbing particles on glacier surfaces” are part of the reason. Read the full report here.   Spread the...

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Photo Friday: Cryoconites and Glacier Tables

Posted by on May 29, 2015 in All Posts, Featured Posts, Images, Science | 0 comments

Photo Friday: Cryoconites and Glacier Tables

Spread the News:ShareHave you ever seen dark cavities on glaciers, which are also referred to as “cryoconites”? These holes, which can be meters deep,are created from debris on top of glaciers. Dark-colored debris, including soot, dust, and pollen, speed up the melting process of glacial ice as a consequence of their low reflectivity to incoming sunlight. In some cases, glacial surface debris can also form pits in the ice through chemical melting. Hence, most of the glacial thaw holes are filled with melt-water, which become home to cyanobacteria, fungi, and other microbes. However, some large solid debris, in particular boulders, will prevent the ice beneath from melting as surrounding ice, forming glacier tables. Here are some photographs of cryoconites and glacier tables. Learn more about glacial surface debris here.   Glacier Table ©2010 Florian Mair Glacier Thaw Hole Source: Galia & Yoav/Flickr Cryoconites Source: Sandwich/Flickr Glacier Thaw Hole Source: Andrew E. Russell/Flickr Spread the...

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Roundup: Black Carbon, Winds, and Supraglacial Lakes

Posted by on May 4, 2015 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Black Carbon, Winds, and Supraglacial Lakes

Spread the News:ShareLight-absorbing Particles in Peru “Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of lightabsorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru.” Read more here. Winds on Glaciers “We investigate properties of the turbulent flow and sensible heat fluxes in the atmospheric surface layer of the high elevation tropical Zongo glacier (Bolivia) from data collected in the dry season from July to August 2007, with an eddy-covariance system and a 6-m mast for wind speed and temperature profiles. Focus is on the predominant downslope wind regime.” Read more here. Supraglacial Lakes in Central Karakoram Himalaya “This paper discusses the formation and variations of supraglacial lakes on the Baltoro glacier system in the Central Karakoram Himalaya during the last four decades. We mapped supraglacial lakes on the Baltoro Glacier from 1978 to 2014 using Landsat MSS, TM, ETM+ and LCDM images. Most of the glacial lakes were formed or expanded during the late 1970s to 2008. After 2008, the total number and the area of glacial lakes were found to be lesser compared to previous years.” Read more here.   Spread the...

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Roundup: Rock Avalanche, Melting Sound, Black Carbon

Posted by on Mar 23, 2015 in All Posts, Featured Posts, News, Roundup, Science | 0 comments

Roundup: Rock Avalanche, Melting Sound, Black Carbon

Spread the News:ShareLandslides on Glaciers “The chapter looks mainly at massive rock slope failures that generate high-speed, long- runout rock avalanches onto glaciers in high mountains, from subpolar through tropical latitudes. Drastic modifications of mountain landscapes and destructive impacts occur, and initiate other, longer-term hazards. Worst-case calamities are where mass flows continue into inhabited areas below the glaciers. Travel over glaciers can change landslide dynamics and amplify the speed and length of runout.” Read more about this chapter here.   Noise from Melting Glaciers “According to research accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union, the underwater noise levels are much louder than previously thought, which leads scientists to ask how the noise levels influence the behavior of harbor seals and whales in Alaska’s fjords.” Read more of this article.   Black Carbon in Tibetan Plateau “High temporal resolution measurements of black carbon (BC) and organic carbon (OC) covering the time period of 1956–2006 in an ice core over the southeastern Tibetan Plateau show a distinct seasonal dependence of BC and OC with higher respective concentrations but a lower OC / BC ratio in the non-monsoon season than during the summer monsoon. We use a global aerosol-climate model, in which BC emitted from different source regions can be explicitly tracked, to quantify BC source–receptor relationships between four Asian source regions and the southeastern Tibetan Plateau as a receptor.” Read the paper here.     Spread the...

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Roundup: New Stories on Black Carbon

Posted by on Jan 26, 2015 in All Posts, Featured Posts, Images, News, Science | 0 comments

Roundup: New Stories on Black Carbon

Spread the News:ShareWe feature three stories, all of which focus on black carbon. This atmospheric pollutant plays an important role in accelerating glacier retreat. Moreover, policies can be designed to reduce it, by supporting alternative fuels and improved technologies. Reductions in black carbon also bring health benefits, since this substance leads to pulmonary diseases. Story 1: Ice Core Data from Svalbard “The inner part of a 125 m deep ice core from Holtedahlfonna glacier (79◦8 N, 13◦2 E, 1150 m a.s.l.) was melted, filtered through a quartz fibre filter and analysed for EC using a thermal–optical method. The EC values started to increase after 1850 and peaked around 1910, similar to ice core records from Greenland. Strikingly, the EC values again increase rapidly between 1970 and 2004 after a temporary low point around 1970, reaching unprecedented values in the 1990s. This rise is not seen in Greenland ice cores, and it seems to contradict atmospheric BC measurements indicating generally decreasing atmospheric BC concentrations since 1989 in the Arctic.” Read more about this research here.   Story 2: Black Carbon over the Himalayas and Tibetan Plateau “Black carbon (BC) particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions 5 and emission sectors, it is essential to quantify the source–receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. ” Read more about this research here.   Story 3: Modeling of Climatic and Hydrological Impacts “Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance (a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high.” Read more about this research here.   Spread the...

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